Impact of clay soil on improved hillside drainage
Good morning, I live in a lovely condo community, constructed on a series of terraces on a wooded hillside in Silver Spring, Maryland. The front hillside from street was barren, clay-type soil when I came 14 years ago; I amended the soil slowly with peat moss and planted ivy. It improved the front area drainage a lot. I now have the same issue (becomes a floodway during rains) on the 'worn' pathways used by neighbors in back yards. How much would soil amendments help improve water retention/reduce erosion and soil compaction? Other options are adding woodchips to pathways to reduce erosion, or going with permeable pavers (much more expensive!) but probably good longterm. Thanks for any information about these options or pointing me to research you know of. Do your experts come out and provide (free?) consulting services to condo communities with erosion problems? Thanks for your help,
Montgomery County Maryland
Trails or paths on hillsides are a difficult problem (which parks constantly have to address.)
Yes, adding organic amendments to soil helps it absorb more water, but that will not compensate for heavy foot traffic.
Making the paths winding in gradual 'S' shapes, will slow water.
Also, a major solution is adding horizontal branches or landscape ties that essentially terrace the path to slow runoff.
Mulch will definitely slow rain runoff, but heavy rainfall will wash mulch away, depending upon the grade of the hill and the amount of rain.
You may want to do a combination, or all, of these suggestions.
(Incidentally, English ivy is considered a non-native invasive plant in Maryland, so we don't recommend planting more of it. If this is what you have, you probably keep it in bounds, but it should never be allowing to climb up trees because there it can mature, produce berries, and spread to parks and natural areas.)
Some jurisdictions will help pay for stormwater remediation. Montgomery has a program which may help you design and pay for this: http://extension.umd.edu/watershed/watershed-resources